nissans variable valve timing

[Thesil]

since the z forums are basically dead I figured a question like this would probably be best answered here.

Just post what you know about it

[UncleBen]

its a type of valve timing system, a type of "vtec", except Nissan's version. thats basically it. oh, and it makes a bulge in the valve cover on the s14 and s15 black top sr's

[EZcheese15]

its a type of valve timing system, a type of "vtec", except Nissan's version. thats basically it. oh, and it makes a bulge in the valve cover on the s14 and s15 black top sr's

Not quite.

Nissan's VVT is nothing like VTEC.

There are 3 basic types of variable cam timing and/or lift. Nissan VVT is the simplist version of it. Nissan VVT, and other systems such as Toyota's VVt-i (Variable valve timing with intelligence), work in the same way, but using an electronically actuated switch on the end of the intake cam to advance or retard the intake cam for better power at different RPMs.

The 2nd stage of variable timing is known as Variable timing and lift control. This is what VTEC is (Variable Timing Engine Control). Nissan does have a similar system, known as VVL (Variable Valve Lift). Toyota's version is known as VVt-li (Variable Valve timing with lift intelligence). This system not only has the variable intake cam described in the first stage, but also has variable lift. It works by having two seperate cam lobes on the intake cam. One is for lower rpm's and the other is for higher rpm's. At a certain RPM, the valvetrain locks the second lobe into place, and gives the engine a higher lift, creating more power.

The third stage uses infinitly variable lift. BMW is currently developing this system (not sure if it is in production yet), but it uses a variable system that the intake valve rides on so that it's opening point can change infinitly different opening heights.

Ofcourse, with all these systems, there is about 100 different versions and spin offs. This is just a basic, short, and simple explaination.